High-resolution structure of an archaeal zinc ribbon defines a general architectural motif in eukaryotic RNA polymerases

61Citations
Citations of this article
16Readers
Mendeley users who have this article in their library.

Abstract

Background: Transcriptional initiation and elongation provide control points in gene expression. Eukaryotic RNA polymerase II subunit 9 (RPB9) regulates start-site selection and elongational arrest. RPB9 contains Cys 4 Zn 2+ -binding motifs which are conserved in archaea and homologous to those of the general transcription factors TFIIB and TFIIS. Results: The structure of an RPB9 domain from the hyperthermophilic archaeon Thermococcus celer was determined at high resolution by NMR spectroscopy. The structure consists of an apical tetrahedral Zn 2+ -binding site, central β sheet and disordered loop. Although the structure lacks a globular hydrophobic core, the two surfaces of the β sheet each contain well ordered aromatic rings engaged in serial edge-to-face interactions. Basic sidechains are clustered near the Zn 2+ -binding site. The disordered loop contains sidechains conserved in TFIIS, including acidic residues essential for the stimulation of transcriptional elongation. Conclusions: The planar architecture of the RPB9 zinc ribbon - distinct from that of a conventional globular domain - can accommodate significant differences in the alignment of polar, non-polar and charged sidechains. Such divergence is associated with local and non-local changes in structure. The RPB9 structure is distinguished by a fourth β strand (extending the central sheet) in a well ordered N-terminal segment and also differs from TFIIS (but not TFIIB) in the orientation of its apical Zn 2+ -binding site. Cys 4 Zn 2+ -binding sites with distinct patterns of polar, non-polar and charged residues are conserved among unrelated RNAP subunits and predicted to form variant zinc ribbons.

Cite

CITATION STYLE

APA

Wang, B., Jones, D. N. M., Kaine, B. P., & Weiss, M. A. (1998). High-resolution structure of an archaeal zinc ribbon defines a general architectural motif in eukaryotic RNA polymerases. Structure, 6(5), 555–569. https://doi.org/10.1016/S0969-2126(98)00058-6

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free